Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_2/V16NO225.TXT

Internet Message Format | 1993-07-13 | 30KB

Date: Thu, 25 Feb 93 05:04:57
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #225
To: Space Digest Readers
Precedence: bulk


Space Digest                Thu, 25 Feb 93       Volume 16 : Issue 225

Today's Topics:
                  Beamed power transmission on Mars?
                         Elements -> AZ,ELEV
                  Getting people into Space Program!
           HELP, PLEASE!  with USRA Design Project (2 msgs)
                 How many RPM's around his own axle c
                   Human Distance Record:Apollo 13
                LOAN space station money to a company?
               Looking for astronaut plastic figures...
                    Mars Rescue Mission, what if!
                            Neil Armstrong
                       NOAA, METEOR satellites
                  Nobody cares about Fred? (2 msgs)
                  Plans for Phobos/Diemos? (2 msgs)
             Revised RESULT: sci.geo.eosdis fails 112:14
          Sex and Subject Lines (was Re: Sabatier Reactors.)
         unnecceary violence (was: Nobody cares about Fred?)
         Weekly reminder for Frequently Asked Questions list

    Welcome to the Space Digest!!  Please send your messages to
    "[e-mail]", and (un)subscription requests of the form
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    (THENET), or [e-mail] (Internet).
----------------------------------------------------------------------

Date: 23 Feb 93 20:44:01 GMT
From: Tim Thompson <[e-mail]>
Subject: Beamed power transmission on Mars?
Newsgroups: sci.space

   I will express the opinion that this is not a practical idea. First, since
Mars has little atmosphere, an orbiting receiver will not be all that much more
efficient than solar cells on the ground (or on a rover, etc.). Nothing to be
gained by being in orbit, except maybe size.
   Using a laser to beam power down isn't a hot idea because the laser takes a
lot of power to generate, and it's hard to convert at the bottom, microwaves are
a much better idea. However, the notion of beaming power down by miocrowaves has
been explored for the earth, and found impractical from an engineering standpoint.
As I recall there were severe problems keeping the signal from various parts of
a large antenna (or antenna array) in phase, to prevent destructive interference.

---
ALL OPINIONS EXPRESSED ARE MINE ALONE. BELIEVE THEM AT YOUR OWN DISCRETION. I DO.
------------------------------------------------------------
Timothy J. Thompson, Earth and Space Sciences Division, JPL.
Assistant Administrator, Division Science Computing Network.
Secretary, Los Angeles Astronomical Society.
Member, BOD, Mount Wilson Observatory Association.

INTERnet/BITnet:    [e-mail]
NSI/DECnet:         jplsc8::tim
SCREAMnet:          YO!! TIM!!
GPSnet:             118:10:22.85 W by 34:11:58.27 N

------------------------------

Date: 23 Feb 93 19:41:07 GMT
From: Scott Coffeen <[e-mail]>
Subject: Elements -> AZ,ELEV
Newsgroups: sci.space,sci.astro

Hello.

   I am looking for a book of equations necessary to convert satellite orbital
elements into azimuth and elevation. I can't use a computer, I must work it
all out by hand (That's what college is all about!) I was wondering if there
was a book by NASA on the subject. I checked the FAQ but I really didn't see
anything that helped.

   Thanks!

--
    --= Scott Coffeen  -  Georgia Tech  -  [e-mail] =--

------------------------------

Date: 23 Feb 93 19:40:51 GMT
From: Pat <[e-mail]>
Subject: Getting people into Space Program!
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Dave Michelson) writes:
|  ----------------------------------
|                           199  19
|  ----------------------------------
|
|Of 12 X-15 pilots, it appears that 8 earned astronaut wings.
|
|
|---
|Dave Michelson                             University of British Columbia
|[e-mail]                                  Antenna Laboratory


I didn't realize the percentage of "Space" X-15 fligts were so low.
But the basic concept still stands.  That A "Research" vehicle
undergoing a "Dynamic test routine"  was able to maintain an
average flight level higher then a "Operational"  shuttle system.
And that said research vehicle was able to achieve regular routine
access to space.  Granted tehy are two entirely difficult vehicles,
but it si only lately, 33 some years after the x-15 flew that
the STS is able to achieve a flight rate vaguely like the x-15.
Sortie rates are very important from an operations viewpoint,
and the shuttle has had a great deal of difficulty achieving
a reasonable sorty rate.

pat

------------------------------

Date: Tue, 23 Feb 1993 16:08:20 GMT
From: John Collins <[e-mail]>
Subject: HELP, PLEASE!  with USRA Design Project
Newsgroups: sci.space

To anyone interested,

    The University of Cincinnati's Aerospace Engineering Senior Design
    Project this year is part of the USRA Senior Design Project,
    sponsored by NASA.  I am a member of this design team and our task
    is to design a lunar transportation system for travel between the
    lunar equitorial region and the northern polar region.  (Our whole
    design project is based on the premise that ice has been discovered
    in the northern polar regions of the moon and will be mined,
    processed, and used for fuel and life support).
    We already have some preliminary calculations completed and have
    a general idea of what the vehicle will look like, but if anyone
    out there has any ideas (e.g., pictures, descriptions, other
    journal articles that we can reference),  please feel free to
        throw them this way!  We need all the support we can get.

...                    Thanks a lot,

                        John Collins
                        [e-mail]

------------------------------

Date: Tue, 23 Feb 1993 16:09:56 GMT
From: John Collins <[e-mail]>
Subject: HELP, PLEASE!  with USRA Design Project
Newsgroups: sci.space

To anyone interested,

    The University of Cincinnati's Aerospace Engineering Senior Design
    Project this year is part of the USRA Senior Design Project,
    sponsored by NASA.  I am a member of this design team and our task
    is to design a lunar transportation system for travel between the
    lunar equitorial region and the northern polar region.  (Our whole
    design project is based on the premise that ice has been discovered
    in the northern polar regions of the moon and will be mined,
    processed, and used for fuel and life support).
    We already have some preliminary calculations completed and have
    a general idea of what the vehicle will look like, but if anyone
    out there has any ideas (e.g., pictures, descriptions, other
    journal articles that we can reference),  please feel free to
        throw them this way!  We need all the support we can get.

...                    Thanks a lot,

                        John Collins
                        [e-mail]

------------------------------

Date: 24 Feb 93 12:32:27 GMT
From: Steve Grant <[e-mail]>
Subject: How many RPM's around his own axle c
Newsgroups: sci.space

> This guy would get along well with the rec pyrotechnicas crowd....

  Hehehe, I tend to agree, not that there is anything wrong with them...

  Steve Grant

------------------------------

Date: Tue, 23 Feb 1993 19:09:11 GMT
From: Dillon Pyron <[e-mail]>
Subject: Human Distance Record:Apollo 13
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Paul Carter) writes:
>The answer to who holds the record distance from Earth is the crew of
>Apollo 13. They achieved 400,187 km (248,655 imperials).
>The crew were Capt. James Lovell, Fred Haise and John Swigert.

Okay, now for a toughie (I don't know the answer, I'm really looking for it).

Who was the loneliest man in the Universe?  In other words, which of the Apollo
"third men" got furthest from his teammates, and was, hence furtherest from any
living human?  That we know of  :-)
>
  [deleted]
>
>Anyway, I wonder exactly WHO was at the back of the Apollo 13 can when
>it made history ?
Weren't they actually in the rather cozy LM?
>
--
Dillon Pyron                      | The opinions expressed are those of the
TI/DSEG Lewisville VAX Support    | sender unless otherwise stated.
[phone] (when I'm here)     |
[phone] (when I'm home)     |No people gave up their rights all at once.
[e-mail]          |Preserve the Bill of Rights.
PADI DM-54909                     |Protect the Second Amendment.

------------------------------

Date: Tue, 23 Feb 1993 21:07:11 GMT
From: Jeff Bytof <[e-mail]>
Subject: LOAN space station money to a company?
Newsgroups: sci.space

Maybe it would be better just to loan a capable company the
money to design and build a space station for its own purposes.
Probably a station designed and run by a company would be smaller,
more cost effective and have more highly focused objectives than
one that NASA comes up with.

-rabjab

------------------------------

Date: Tue, 23 Feb 1993 14:09:22 EST
From: [e-mail]
Subject: Looking for astronaut plastic figures...
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Craig
Keithley) says:

>In article <[e-mail]>, [e-mail] (Daniel
>A. Segel) wrote:
>>
>> I'm looking for some plastic figures, about 6" high, of astronauts
>> doing various astronaut-like things such as planting a flag, holding
>> a camera, etc.
>>

>Geez...  That brings back memories of Major Matt Mason (sic?).  About the
>same size as and functionality as GI-JOE.  Lets see, it was late sixties,
>early seventies.  They're probably collectors items now.  Lots of neat moon
>rovers, etc.  Sigh.  I'd probably pay for one if it was in good enough
>condition...

>Craig Keithley
>Apple Computer, Inc.
>[e-mail]

       How about Billy Blastoff! When I was around 10 in 69 and
       was watching the Apollo missions, Billy was alway with me. :-)
       I think I might still have him and all his equipment.

------------------------------

Date: 23 Feb 93 20:45:56 GMT
From: Keith A Taylor <[e-mail]>
Subject: Mars Rescue Mission, what if!
Newsgroups: sci.space

The obvious way to deal with Mars rescue is to send an unmanned Mars station/
return vehicle before you ever send a crew. Granted, this doesn't solve all
failure modes. Also, this is expensive enough that it might not be done. But,
who said going to Mars was cheap. Losing a crew in a maximum-visibility
situation is a very unattractive contingency.

The other benefit of a prepositioned return ship is that you can preposition
lots of equipment and supplies. And, you can send the first ship via a
minimum-energy orbit (read: long) and maybe send the crew on a faster transfer
orbit with less supplies and less mass, making the faster transfer orbit
feasible.

Keith Taylor    Tektronix    DPL Eng.

------------------------------

Date: Tue, 23 Feb 1993 19:00:29 GMT
From: Dillon Pyron <[e-mail]>
Subject: Neil Armstrong
Newsgroups: sci.space,sci.astro

In article <[e-mail]>, [e-mail] (CLAUDIO OLIVEIRA EGALON) writes:
>
>> Does anyone know the current whereabouts of Neil Armstrong?
>> What does he do these days?
>
>
>According to a letter that  Neil Armstrong wrote to the people that was organizing
>the X-15 First Flight 30th Aniversary Celebration in June 1989 at Ames, at that time
>he was working at NASA Headquarters. I do not know if he is still there but since
>that letter was written almost   four years ago,  it is likely that he is still there.

I last saw him on TDC on a show called _X-Planes_.  He looked good.  Better
than I at twice my age!  He appears to be the "guest co-host" or something.  On
one episode, he was talking about the smooth flying characteristics of the F16
in the transonic range and how that all came from the XB70, and then spoke of
his flight "day before yesterday"!
--
Dillon Pyron                      | The opinions expressed are those of the
TI/DSEG Lewisville VAX Support    | sender unless otherwise stated.
[phone] (when I'm here)     |
[phone] (when I'm home)     |No people gave up their rights all at once.
[e-mail]          |Preserve the Bill of Rights.
PADI DM-54909                     |Protect the Second Amendment.

------------------------------

Date: 23 Feb 93 18:31:36 GMT
From: George Hastings <[e-mail]>
Subject: NOAA, METEOR satellites
Newsgroups: sci.space

Ron McCarty (Ron McCarty ) writes:
>
> Message-ID: <[e-mail]>
> Newsgroups: sci.space
> Subject: NOAA, METEOR satellites
> Lines: 16
>
> We have set up a satellite receiving station and are receiving
> images from NOAA and Meteor (Russian) satellites. We would like
> to correspond with others who are doing this or who are interested
> in doing this. We are a branch college of Penn State, located in
> in Erie PA. We hope to get some programs going with local elementary
> and high schools to get students interested in science at an early
> age. We also hope to get our own students involved in some undergraduate
> research projects. We have faculty involved from computer science, physics,
> biology and geoscience. As I said, we would like to correspond with others
> who have like interests so we can pool our knowledge/resources/experiences.
> Please respond by e-mail or followup, whichever yo

   Here at the Mathematics & Science Center in Richmond, VA, we
have just started on a similar venture. We are a regional K-12
consortium serving the City of Richmond, and the five
surrounding counties. We operate a local BBS where we have a
DownLoad section for GOES, METEOR, and NOAA Polar Orbiter
images available in GIF format.
   I'm sure that you have already discovered that one problem
with digitized images is that they do take up a LOT of storage
space. I find that typically, one GIF weather image is just
about 1050 XMODEM blocks. Assuming that users have 2400 baud
modems, that is a little over ten minutes to DL an image. With
a single telephone line in, I can foresee that if DLing WX
images becomes popular, we will have to consider multiple lines
in, and both our BBS and users will want to move up to
high-speed data transfer with more capable modems.
   I'm also VERY interested in continuing this discussion, and
hearing what you and others are doing, experimenting with, or
considering in this area!
 ____________________________________________________________
| George Hastings        [e-mail] |
| Space Science Teacher        [e-mail]      |  If it's not
| Mathematics & Science Center     STAREACH BBS: 804-343-6533   |   FUN, it's
| 2304 Hartman Street        OFFICE:       804-343-6525   |  probably not
| Richmond, VA 23223        FAX:          [phone]   |    SCIENCE!
 ------------------------------------------------------------

------------------------------

Date: 23 Feb 93 19:51:32 GMT
From: Pat <[e-mail]>
Subject: Nobody cares about Fred?
Newsgroups: sci.space

Tom munoz does an excellent job of explaining the PM changeout
sequence, the costs, weights, hazards and times involved.
My original post which started a lot of this was that Freedom
should have been designing on hte basis of Methane thrusters.
Methane/LOX is close in impulse to hydrazine.  Plus Methane
can be generated from byproducts of a station life support system.
Methane is also not toxic(in low quantity), corrosive(much)
and doesn't have to hauled up to orbit in  10KDollar/lb  rockets.

plus the LOX can be diverted to and from life support, and the methane
can even be cracked as fuel stocks for basic chemical
processses.

All in all, a reasonable alternative fuel, but my understnading
from the trade press was the Freedom PMO waived off because not
enough knowledge base existed on methane thrusters.

This kind of failure seeking management ultimately brought the
prgram down.

pat

------------------------------

Date: Tue, 23 Feb 1993 20:39:02 GMT
From: Brad Whitehurst <[e-mail]>
Subject: Nobody cares about Fred?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Mary Shafer) writes:
>On Tue, 23 Feb 1993 16:23:20 GMT, [e-mail] (fred j mccall 575-3539) said:
>
>FMC> Of course, you probably also want to say that the
>FMC> Tacoma Narrows bridge was a *software* failure, too.  So tell me
>FMC> again how there's no such thing as software engineering because
>FMC> it isn't predictable and well understood like 'real' engineering
>FMC> -- like, say, bridge design and construction . . .
>
>Actually, the Tacoma Narrows bridge isn't a very good example of a
>failure in understanding and predicting physical phenomena.  Structural
>resonance was not well understood at the time and the unique site was
>not recognized as being likely to induce the problem.
>
>However, the bridge built 20 years later in Tennessee (?) in the same
>sort of terrain that failed in exactly same manner was.
>
>Every dog (profession) is allowed one bite.
>
>Comets and their window corners, Electras and their whirl modes,
>swept-wing aircraft and inertial coupling....  If you constrain
>designers to never make errors you also constrain them to never do
>anything new.
>
>On the other hand, if we built buildings the way we write software,
>the first woodpecker to come along would have destroyed civilization.
>
>--
>Mary Shafer  DoD #0362 KotFR NASA Dryden Flight Research Facility, Edwards, CA
>[e-mail]                    Of course I don't speak for NASA
> "A MiG at your six is better than no MiG at all."  Unknown US fighter pilot

    Good analogy, Mary!  I'll have to remember that one.  One
thing that disturbs me about many graduating engineers (that I've
either worked with or taught) is a disturbing tendency to believe too
much in the computer answers.  Even mechies lean to the computer
answers, and are profoundly disturbed when real life doesn't match the
model.  They hated me in the lab I taught, because I'd give'em a
"Tough.  That's the real world for ya."  when the graphs don't match!
I thought I was bad enough, when I had a calculator that would give me
10 digit "accuracy"! :-) To borrow/turn a phrase:  "Measure twice, cut
once.  Then cut again when it doesn't fit!"
--

Brad Whitehurst    |   Aerospace Research Lab
[e-mail] |   We like it hot...and fast.

------------------------------

Date: 23 Feb 1993 19:18 UT
From: Ron Baalke <[e-mail]>
Subject: Plans for Phobos/Diemos?
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Jeff Bytof) writes...
>Are there any current plans to land in Phobos and/or Diemos?
>

No plans at the moment.  The Soviets' Phobos mission in 1989 would have landed
"hoppers" on Phobos, but both spacecraft failed before being able to
achieve this.

There is a resurgence of Mars missions this decade.  Mars Observer
is on its way and will arrive in August.  The Soviets will launch a spacecraft
to Mars in 1994 and another one in 1996.  The MESUR mission (still pending
approval) would send 16 landers to Mars, the first launch scheduled for
1996.
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | [e-mail]
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | If you don't stand for
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | something, you'll fall
|_____|/  |_|/       |_____|/                     | for anything.

------------------------------

Date: Tue, 23 Feb 1993 18:10:24 GMT
From: Ed McCreary <[e-mail]>
Subject: Plans for Phobos/Diemos?
Newsgroups: sci.space

>>>>> On Tue, 23 Feb 1993 18:05:16 GMT, [e-mail] (Jeff Bytof) said:
JB> Are there any current plans to land in Phobos and/or Diemos?

The last Soviet mission to mars was going to land a "hopper" on Phobos.
It would hop around on a pogo stick like mechanism and collect samples
for remote analysis.

Unfortunately, the soviets have never been very lucky with mars missions
and either gremlins or BEMs got to both probes.

I'm not aware of any other plans in the works, but I could be wrong.


--
Ed McCreary                                               ,__o
[e-mail]                           _-\_<,
"If it were not for laughter, there would be no Tao."  (*)/'(*)

------------------------------

Date: 23 Feb 93 10:14:54 GMT
From: Cindy Posinski <[e-mail]>
Subject: Revised RESULT: sci.geo.eosdis fails 112:14
Newsgroups: news.announce.newgroups,news.groups,sci.space,sci.astro,sci.geo.fluids,sci.geo.geology,sci.geo.meteorology

    The vote for the sci.geo.eosdis newsgroup has failed due to two
duplicate votes.  Due to this error the final vote tally is 112 YES
votes to 14 NO votes.  [[ Moderator's note: requirements for passage
are that there be at least 100 more YES than NO votes -- tale ]]

    For the people who voted for creation of the newsgroup, we have
a local newsgroup named gsfc.eos which we will be happy to provide you
access to to read, save and post Earth Observing System Data Information
Service (EOSDIS) information.

    Included in this newsgroup are postings of Earth Observing System
(EOS) related newsletters and articles along with posting from
interested users and members of the EOSDIS community.

        Newsletters and news articles which will be posted to this
newsgroup on a regular basis include:

                  The Earth Observer
                  The Processor
                  ESDIS Weekly
                  EOS News

    If you are interested in access to gsfc.eos please contact me at
[e-mail].

    Thank you to all who participated in the voting process.

Cindy Posinski

------------------------------

Date: 23 Feb 93 12:40:23 -0600
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject: Sex and Subject Lines (was Re: Sabatier Reactors.)
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Pat) writes:
> In article <[e-mail]> [e-mail] (fred j mccall 575-3539) writes:
[something Pat disagreed with]
>
> Fred.
>     Perhaps you should read all of the thread before posting.
[rest of argument deleted]

Hah!  What a spectacle!  Pat lectures somebody else on netiquette, but
hasn't changed the "Subject:" line in this month-old thread.

I checked; the last time anybody actually discussed Sabatier reactors
was 27 January.

People, could you modify your subject lines so they reflect what
you're actually talking about?


(I think I'll put the word "sex" in the subject of this one so
everyone will read my plea.)

Bill Higgins, Beam Jockey              | "Based on the antiproton
Fermi National Accelerator Laboratory  | decay, I would estimate the
Bitnet:           [e-mail]  | incident occurred
Internet:       [e-mail]  | within the last 4.3 hours."
SPAN/Hepnet:           43011::HIGGINS  |         --Mr. Data

------------------------------

Date: Tue, 23 Feb 1993 19:28:27 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: unnecceary violence (was: Nobody cares about Fred?)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:

>However, the initial point stands.  Mr. Sherzer will not be happy until every
>stinkin' burrrreo-crat in NASA is unemployed and out on the street, so America
>(waive flag for knee-jerk reaction) can once again
>assume it's manifest destiny in the Universe.
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Hmmm.... A few months ago I was the enemy of all Loyal Americans because I
was out to destroy the US aerospace insustry and give it to the Russians
by buying a few Soyuz's.

Now, I'm the number one agent of US flag waving and manifest destiny.

$5 to whoever can tell me just when I changed sides (Doug will be the judge
since he seems to be the only one who knows). Boy this New World Order sure
is confusing!

  Allen
--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------112 DAYS TO FIRST FLIGHT OF DCX----------------------+

------------------------------

Date: 23 Feb 1993 14:46:15 -0500
From: Jon Leech <[e-mail]>
Subject: Weekly reminder for Frequently Asked Questions list
Newsgroups: sci.space,sci.astro,sci.space.shuttle

    This notice will be posted weekly in sci.space, sci.astro, and
sci.space.shuttle.

    The Frequently Asked Questions (FAQ) list for sci.space and sci.astro is
posted approximately monthly. It also covers many questions that come up on
sci.space.shuttle (for shuttle launch dates, see below).

    The FAQ is posted with a long expiration date, so a copy may be in your
news spool directory (look at old articles in sci.space). If not, here are
two ways to get a copy without waiting for the next posting:

    (1) If your machine is on the Internet, it can be obtained by anonymous
FTP from the SPACE archive at ames.arc.nasa.gov (128.102.18.3) in directory
pub/SPACE/FAQ.

    (2) Otherwise, send email to '[e-mail]'
containing the single line:

help

    The archive server will return directions on how to use it. To get an
index of files in the FAQ directory, send email containing the lines:

send space FAQ/Index
send space FAQ/faq1

    Use these files as a guide to which other files to retrieve to answer
your questions.

    Shuttle launch dates are posted by Ken Hollis periodically in
sci.space.shuttle. A copy of his manifest is now available in the Ames
archive in pub/SPACE/FAQ/manifest and may be requested from the email
archive-server with 'send space FAQ/manifest'. Please get this document
instead of posting requests for information on launches and landings.

    Do not post followups to this article; respond to the author.

------------------------------

Newsgroups: sci.space

From: tomas o munoz 283-4072 <[e-mail]>
Subject: Re: Nobody cares about Fred?
Message-Id: <[e-mail]>
Sender: tomas o munoz 283-4072 <munoz@lurch>
Organization: MDSSC
References: <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>
Date: Tue, 23 Feb 1993 17:47:43 GMT
Lines: 58
Source-Info:  Sender is really [e-mail]
Source-Info:  Sender is really [e-mail]

In article <[e-mail]>, [e-mail] (Allen W. Sherzer) writes:

|> >Again, it's not the lack of EVA, it's the fact that you don't want
|> >hydrazine all over the EVA crew.
|>
|> But the Russians with their backward space program don't find that to
|> be a problem. Surely with our better technology we could refuel them
|> in orbit possible saving billions of $$ in life cycle cost.

If we really wanted to save life cycle costs, we would have stayed with
the O2/H2 propulsion system before the current modular prop module
design was implemented due to upfront savings.  The O2/H2 system
used water from Shuttle fuel cells and electrolysis to get the propellant
and the catalyst.  However O2/H2 was more expensive than prop modules
up front.  Life cycle - O2/H2 is a dream while modules are a nightmare.

|> >Thrusters will stay in orbit for years at a time.  They will be inspected
|> >and/or refurbished every time they are returned to earth.
|>
|> This sort of thruster is used by every satellite in existance. They are
|> extremely reliable and shouldn't need servicing this often.

Agreed.  I assume you mean unmanned satellites, not man-rated vehicles.


|> >There's alot more to it than launching it - that's the easy part.
|>
|> Well the Russians have this problem solved. I'm sure we can. Doing so
|> is after all, worth a lot of money.

I agree totally.


|> >I don't think the OMS are big enough to fuel both orbiter and SSF.
|>
|> Well then maybe they can be refueled with expendables. That will save
|> even more money.

The problem I have with this suggestion is that you're talking about
adding another system, starting up a new program.  Although an ELV could
probably do it cheaper, you still need the Shuttle.  Therefore,
you have the cost for two separate launch systems.

ELVs present several other logistics nightmares.  Although you could build
them to deliver whatever you want, how do you get stuff down.  There
are many other disadvantages to ELVs and many advantages as well.

--
========================================================================
Tom Munoz     |   [e-mail]

Thought for the day [plagiarized from someone else]:

Engineers think equations are an approximation of reality.
Physicists think reality is an approximation of the equations.
Mathematicians never make the connection.
========================================================================

------------------------------

End of Space Digest Volume 16 : Issue 225
------------------------------